Heating apparatus



Aug. 21,- 1945. w. A. GRlSWOLD HEATING APPARATUS 1941 3 Sheets-Sheet lFiled oct. .21,

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A1 vonygns `Aug.`21, 1945. W. A. GRISWOLD HEATING APPARATUS Filed Oct.2l, 1941 5 Sheets-Sheet 2 vn3. E

I NVENTOR mmm A. mswow ATTORNEYS Aug. 21., l1945. w. A. GRISWOLD HEATING'APPARATUS 3 Sheets-Sheet 5 Filed Oct. 2l

R o T N E V N I ATTORNEYS Patented Aug. 2l, 19`45 UNITED STATES .PATENTOFFICE HEATING APPARATUS William A. Griswold, Cleveland, Tenn.

Application October 21, 1941, Serial No. 415,931

Claims.

This invention relates to coal burning heating appliances.

It is the object of the invention to provide a coal burning heatingappliance capable of consuming substantially all smoke and volatilegases, so as to secure the heating value thereof instead of permittingthem to be wasted by being discharged through the chimney.

It is a further object of this invention to provide such combustion thatthe appliance is economical to operate by introducing `the properquantity of air in the right areas above the fuel to ensure completecombustion of all volatile matter so that the smoke and combustiblegases escaping are reduced to the minimum.

It is a further object to provide by the substantially completeconsumption of combustible gases and by the elimination of the exit ofsmoke to reduce the carbon content of thewsmoke to an ash which issuitably collected in the mechanism.

It is a further object to provide a heating appliance which is free fromexplosions due to accumulated gases which have heretofore been afrequent occurrence in heaters of the prior art when the fire box isoverfed with fresh fuel.

It is an additional object to provide a much longer period of burningthe fuel at a low rate.

It is an object of the invention to provide a heating appliance whichcan burn bituminous coals in crowded areas because by this invention aclearI nue discharge is secured regardless of the fuel used.

It is an additional object of the invention to secure improved heatingcharacteristics due to the burning of `the gases atthe top of the repot.

It is a further important object of this inven'- tion to regulate theexit of the gases and smoke and the additional volume of air which ispreheated and supplied over the top of the fuel, so that the gases andsmoke, both combustible solids, and the gases, are consumed in thepresence of the additional oxygen of the additional air before they canescape. This feature of regulating the exit of the gases and smoke whileheating additional air directly adjacent the exit areas, is an importantfeature of this invention.

Referring to the drawings:

Figure 1 is a section taken vertically from front to rear of the heatingappliance;

Figure 2 is a front elevation of the appliance;

Figure 3 is a top plan view thereof;

Figure 4 is a section on the line 4--4, looking in the direction of thearrows on Figure 1;

Figure 5 is a section on the line 5-5 on Figure 1, looking in thedirection of the arrows;

Figure 6 is a section on Figure l taken on the line 6-6, looking in thedirection of the arrows;

Figure 7 is a modied form of Figure 6, with.

rebrick interllers between the air ducts;

Figure 8 is a section on the line 8 8 on Figure l, looking in thedirection of the arrows; and

Figure 9 is a perspective of the control. flue partionally in section. l

Generally speaking, this invention relates to stoves, furnaces and thelike. It consists in the provision of features which will ensurecomplete combustion of gases rising from burning coal. One of thesefeatures is a baille located near the outlet opening to the flue, thepurpose of this baille being to impede the direct passage of the gasesfrom the center of the combustionarea to the flue, forcing these gasesinstead to flow toward the sides of the stove at its upper portion.Another principal feature directly associated with the rst is the'provision of air ducts which supply oxygen to a ring at the upper partof the fire box for the purpose of supporting the combustion of thegases impeded by the baffle. This air ring is of inverted U crosssection which takes the air from the supply ducts t'two in number) anddistributes it evenly around the upper portion of the stove, the airdischarging into the gas filled chamber around one of the lips oftheinverted U. The air ring is further provided with openings directlythrough the side of the U-shape-d section, these openings lying directlyopposite the two open sides of the baffle. The purpose of these openingsis to throw a draft of air across the path of the outgoing gases,completing the combustion of any which have not been taken care of bythe air ring.

Air is fed from the air ring under-draft, by positioning the air ductsagainst the heated firebrick of the stove. The inventor states that therebrick walls are sufficiently warmed to produce this draft of airwithin a few minutes of building of a fire in the stove.

Adjustable openings are provided at the lower ends of the air ducts, thepositioning of the size of these openings being correlated with that ofthe usual draft opening in the ash pit. Generally speaking, if a veryintense re or heating is desired, the booster openings as well as theconventional draft opening will be set for maximum draft. This willproduce the fastest possible burning of the coal, as well as the fastestpossible supply of oxygen to the products of combustion arising from thecoal. Also generally speaking,

the lowest ring conditions will be accomplished by the smallest openingsat the three draft controls. Variations from these positions will bemade according to the type of coal being used, the characteristics ofthe flue, etc. l'

Referring to the drawings in detail:

I indicates a base supported on legs and serving to mount an outerjacket 2. This outer jacket is provided with air inlet openings 3 and 4at the rear and front respectively, controlled by damper doors 5andySy-which are hinged thereto. This outer jacket may be continuous a eheating appliance or arranged only at the front and rear as illustrated.This jacket 2 forms passageways 'I and 8, the inner walls of which areformed by the jacket or drum 9, which is provided with a frebrick liningI0. This lining is mounted upon a ring II, which is associated with thegrate bars I2. In operation, kindling is placed on the grates |2 andcoal is placed on top of the kindling. The damper I3 is opened t0uncover the opening I4 in the ash pit door I5. The base of the applianceIB supports the ash pan I'I which can be withdrawn through the door I5.-

The ashes from the grate bars I2 and I2a can be dumped into this ashpan. l i

Turning to the top of the heating appliance, it will be noted that theair passing up the passageways l and 8, is heated as it passes over thedrum 9, forming the inner walls of such passageways. This air thenpasses horizontally through the openings I8, in such wall 9, and thencebeneath the ring I9, provided with one or more openings 20, anddepending feet 2I resting upon the top of the firebrick I0. Thus largevolumes of fresh air are mixed at the top of the stove with the coalgases and smoke supplying the additional oxygen necessary at this pointto cause complete combustion of the coal gases and the consumption ofthe smoke. This is facilitated by the dome 22, forming a pressurechamber 23, a part of which is formed by the angular baflie 24,` whichis open at the sides as at 25. Hence,

the air and any entrained gases pass out through the stack 26. Thisarrangement provides a chamber in which this nal consumption of gasesand smoke takes place and in which the final combustion is effected. Bycausing the gases to pass over the baille 24 and make their exit throughthe sides thereof, it is thus possible to restrict the exit of any smokeor gas to prevent the draft from carrying the smoke and gas out of thestack Vor flue pipe 26, before they are fully consumed and combustion iscompleted.

One of the features of my invention is the supply of such additional airin large volume, fresh and warm, into an enlarged chamber with arestricted outlet in addition to the normal draft of air which entersbeneath the grate bars and proceeds upwardly through the fuel. The fuelburns generally on the outer walls of the body of fuel so that thehottest area is onthe outer side and the heat is largely taken up by theincoming cool fresh air which is thence delivered to the top of thefireto secure complete combustion.

It will be understood that the exact size of the fresh air ducts I and8, and the extent to which these ducts enclose the drum 9, is a matterof adjustment and choice.

The dome 22 is hinged as at 22a, so as to form a rocking cover to permitof the introduction of fuel. The other details of construction are notimportant as the primary feature of the invention is the consumption ofsubstantially all the gases and all the smoke by the introduction oflarge volumes of air over the fuel in a chamber with a relativelyrestricted outlet area.

I found that this heating appliance will operate at all temperaturesbetween the lowest which will support combustion of the fuel to that ofa red hot condition. It has been found by experiment that from 80 to 90pounds of bituminous coal will be consumed under hard burningconditions,

` 's is recalled that bituminous coal requires approximately 800 cubicfeet of air per l cubic foot of coal, and 1 pound of coal heated to 500F. produces 6 cubic feet of gas.

The difficulty with burning bituminous coals has been the large smokeand gas discharge which is prohibited in many metropolitan areas. Myinvention, because of its economy and additionally because of this`additional' combustion chamber, completely consumes the coal withlittle or no clinker and leaves only a smallash residue in the center ofthe grate bars.

It will be understoodl that this invention is applicable to any coalburning device and is `not" limited to the construction shown or tostoves, but is adaptable to a wide variety of mechanisms for the heatingof air, food, water and the like.

Having thus fully described my invention, what I claim as new and desire`to secure by Letters Patent is:

l. In a heating appliance of the magazine type, a grate means, a fuelchamber having open ends and an imperforate side wall structurepositioned above said grate with the bottom edge of the chambersubstantially at grate level so that all air that enters the fuelchamber must enter through the open bottom end portion thereof, meansforming a gas combustion chamber directly above the fuel chamber, meansproviding an opening in saidl gas combustion chamber through which fuelis admitted for lling the fuel chamber, means for continuously supplyingpri-` mary air to the fuel chamber through only the open bottom endportion thereof whereby to support combustion in only the lowermostportion of a body of fuel in the fuel chamber and cause hot gasses topass upwardly through the body of fuel in the upper portion of the fuelchamber that is not in alstate of gases therefrom into said gascombustion chamber, means for regulating the quantity of primary airsupplied to the fue] chamber, separate means forming an airdistri-buting ring directly above said'lfuel chamber having the innerperipheral wall thereof substantially in alignment with the innerperipheral surface of the fuel chamber and ,the level of the top edge ofthe fuel chamber which divides the fuel chamber and the gas combustionchamber, said imperforate wall excombustion to drive raw,y

tending to the level of said air discharge opening means to preventadmission of any secondary air into the fuel chamber below the saidlevel, means forming an air passage in thermal association with the fuelchamber having an air inlet opening through which to receive airentirely independent of said primary air connected to said airdistributing ring for conducting secondary air thereto after beingheated 4by its movement through the air passage in thermal associationwith the fuel chamber, means for regulating the quantity of air suppliedthrough said air passage means, and means forming a flue opening fromsaid gas combustion chamber.

2. In a heating appliance of the magazine type, a gratemeans, a fuelchamber having open ends and an imperforate side wall structurepositioned above said grate with the bottom edge of the chambersubstantially at grate level so that all air that enters the fuelchamber must enter through the open bottom end portion thereof, meansforming a gas combustion chamber directly above the fuel chamber, meansproviding an opening in said gas combustion chamber through which fuelis admitted for filling the fue;Av chamber, means for continuouslysupplying pria body of fuel in the fuel chamber and cause hot gases topass upwardly through the body of fuel in the upper portion of the fuelchamber,

that is not in a state of combustion to drive raw gases therefrom intosaid gas combustion chamber, means for regulating the quantity ofprimary air supplied to the fuel chamber, separate means forming aninverted L-shaped air distributing ring positioned directly above saidfuel chamber having the inner peripheral wall thereof substantially inalignment with the inner peripheral surface of the fuel chamber andhaving opening means in the inner peripheral wall of the distributingring immediately adjacent the upper edge of the fuel chamber whereby airreceived in the distributing ring is discharged directly over the upperedge of said fuel chamber and around substantially the entire peripherythereof forming an air blanket at substantially the level of the topedge of the fuel chamber which divides the fuel chamber and ,the gascombustion chamber, said imperforate wall extending to the level of saidair discharge opening means to prevent admission of any secondary airinto the fuel chamber below the said level, means forming an air passagein thermal association with the fuel chamber having an air inlet openingthrough which to receive air entirely independent of said,y primary airconnected to said air distributing ring for conducting secondary airthereto after being heatedby its movement through the air passage inthermal association with the fuel chamber, means for regulating thequantity of air supplied through said air passage means, and

I means forming a flue opening from said gas combustion chamber.

,fair that enters the fuel chamber must enter through the open bottomend portion thereof, means forming a gas combustion chamber directlyabove the fuel chamber, means providing an opening in said gascombustion chamber through which fuel is admitted for lling the fuelchamber, means for continuously supplying primary air to the fuelchamber through only the' open bottom end portion thereof whereby tosupport combustion in only the lowermost portion of a body of fuel inthe fuel chamber and cause hot gases to pass upwardly through the` bodyof fuel in the upper portion of the fuel chamber that is not in a stateof combustion to drive raw gases therefrom into said gas combustionchamber, means for regulating the quantity of primary air supplied tothe fuel chamber, separate means forming an air distributing ringpositioned directly above said fuel chamber having the inner peripheralwall thereof substantially in alignment with the inner peripheralsurface of the fuel chamber and having opening means in the innerperipheral wall of the distributing ring immedately adjacent the upperedge of the fuel chamber whereby air .received in the distributing ringis discharged directly over the upper edge of said fuel chamber andaround substantially the entire periphery thereof forming an air blanketat substantially the level of the top edge of the fuel chamber whichdivides the fuel chamber and the gas combustion chamber, saidimperforate wall extending to the level of said air discharge openingmeans to prevent admission of any secondary air into the fuel chamberbelow the said level, means forming an air passage in thermalassociation with the fuel chamber having an air inlet opening throughwhich to receive air entirely independent of said primary air connectedt0 said air distributing ring for conducting secondary air thereto afterbeing heated by its movement through the air passage in thermalassociation with the fuel chamber, means for regulating the quantity of'air supplied through said air passage means, means forming a ue openingfrom said gas combustion chamber positioned on one side thereof to causeall gases to pass in a uniform direction toward the same for dischargingfrom the gas combustionchamber and xed baffle means disposed in the pathof flow of the gasses in front of and in spaced relationship to saidflue opening to prevent direct flow of gases into the flue opening andthereby retard the movement of gases into the flue opening to causesubstantially complete combustion thereof.

4. In a heating appliance of the magazine type, a grate means, a fuelchamber having open ends and an imperforate side wall structurepositioned above said grate with the bottom edge of the chambersubstantially at grate level so that all air that enters the fuelchamber must enter through the open bottom end portion thereof, meansforming a gas combustion chamber directly above the fuel chamber, meansproviding an opening in said gas combustion chamber through which fuelis admitted for filling the fuel chamber, means for continuouslysupplying primary air to the fuel chamber through only the open bottomend portion thereof whereby to supportv combustion in only the lowermcstportion of a body of fuel in the fuel chamber and cause hot gases topass upwardly through the body of having means in the inner peripheralwall of the distributing ring immediately adjacent the upper edge o-fthe fuel chamber whereby air received in the distributing ring isdischarged directly over the upper edge of said fuel chamber and aroundsubstantially the entire periphery thereof forming an air blanket whichdivides the fuel chamber and the gas combustion chamber, saidimperforate wall extending to the level of said air discharge openingmeans to prevent admission of any secondary air into the fuel chamberbelow the said level, means forming an air passage in thermalassociation with the fuel chamber having an air inlet opening throughwhich to receive air entirely independent of said primary air connectedto said air distributing ring for conducting secondary air thereto afterbeing heated by its movement through the air passage in thermalassociation with the fuel chamber, means for regulating the quantity ofair supplied through said air passage means, means for conveying theconsumed gases from the gas combustion chamber disposed on one sidethereof whereby all of the gases flow through the combustion chamber ina substantially uniform direction toward the `side thereof at which theconveying means is located,

baille means disposed adjacent said conveying meansl and forming anopen-ended chamber there adjacent to. prevent direct flow--of"the gasesinto chamber, means for continuously supplying primary air tothe fuelchamber through only the open bottom end portion thereof whereby tosupport combustion in only the lowermost portion of a body of fuel inthe fuel chamber and cause hot gases to pass upwardly through the bodyof fuel in the upper portion of the fuel chamber that is not in a stateof combustion to drive raw gases therefrom into said gas combustionchamber, means for regulating the quantity of primary air supplied tothe fuel chamber, means forming an air distributing ring directly abovesaid fuel chamber and having opening means therein through which air isdischarged directly over the upper edge of said fuel chamber and aroundsubstantially the entire perihpery thereof forming an air blanket atsubstantially the level of the top edge of the fuel chamber which is thedivision line between the fuel chamber and the gas combustion chamber,said imperforate wall extending to the level of said air dischargeopening means to pre-V vent admission of any secondary air into the fuelchamber below the said level, means forming an air passage in thermalassociation with the fuel chamber having an air inlet opening throughwhich to receive air entirely independent of said primary air connectedto said air distributing ring for conducting secondary air thereto afterbeing heated by its movement through the `air passage the conveyingmeans and thereby forceapcon- 3() in thermal association with the fuelchamber, centration of the gases adjacent each end of said\\means forregulating the quantity of air supballle means just before they passinto the last said chamber and thence into the conveying means, andadditional opening means in said air distributing ring adjacent each ofsaid bafflle means for supplying an additional secondary body of air tolsaid gas combustion chamber above the first mentioned secondary bodydirectly into the concentrated gases in counterow relationship therewithto insure complete combustion ofthe gases before passing into the meansfor conveying the same from the gas combustion chamber.

5. In a heating appliance of the magazine type,

a grate means, a fuel chamber having open ends.

and an imperforate side wall structure positioned above said grate withthe bottom edge of the chamber substantially at grate level so that allair that enters the fuel chamber must enter through the open bottom endportion thereof, means forming a gas combustion chamber directly abovethe fuel chamber, means providing an opening in said gas combustionchamber through which fuel is admitted for filling the fuel liedmhrough.said air passage means, means for conveyinggases from the gascombustion chamber positioned o`n one side thereof whereby to cause thegases to flow in one direction toward said conveying means, a baillemeans disposed adjacent said conveying means to cause the gases flowingtoward the conveying means to separate into independent streams to flowaround the baille means before entering the conveying means, andopenings in said. air distributing ring disposed 'above said firstmentioned openings and located tially complete combustion of the rawgases before entering the means conveying the same away from the gascombustion chamber.

WILLIAM A. GRISWOLD.

